Used as a photosensitizer in photodynamic therapy and imaging applications due to its ability to generate reactive oxygen species upon light exposure. Commonly applied in biological staining for fluorescence microscopy, especially for tracking cellular components and membrane dynamics. Also utilized in the development of optical sensors and dye-sensitized solar cells because of its strong absorption and emission properties in the visible range. Its quaternary ammonium structure enhances cell membrane permeability, making it suitable for live-cell imaging. Additionally, it serves as a precursor in synthesizing fluorescent probes and labels for biomolecules.